[TowerTalk] US Tower 72 ft crank up grinds to a standstill

FritzOAQ fritz at k4oaq.com
Tue May 26 20:38:19 EDT 2020


Many tks to you all fer all the suggestions & help.
Facts I shud have included in my original post:
Tower is 20 yrs old.
The only maint I've done is to change the belt that started slipping.
The rotor is a Yaesu G-2800DXA.
The suggestion that seemed most likely to be the problem was that the oil had drained out of the gear box.
So, I did some reading & learning abt gear boxes.
I discovered I had to get my neighbor who runs a machine shop to grind 1/8 inch or so off an Allen wrench
so it wud fit in that little small spot to loosen the gear box drain.
I tried spraying PB Blaster on it the best I cud. Apparently I shud have waited a few days before trying to loosen it.
I now have an Allen wrench a very artist twist and the opinion there's no way to get the drain loose.
A hammer rather than a paint brush was needed to perform my art work.
I'm anxiously awaiting suggestions of how to turn the tower upside down to drain the oil out of the top hole.
So, moving right along, I assumed the oil didn't need to be drained & filled the oil to the top. I saw no holes on the side to determine when it was full,
so I assumed it was full when it ran over. I'm not sure how much went in but I wud gess between 1/8 to 1/4 of a cup.
I wasn't all that hopeful that that wud fix the prob & sure enuf, prob not solved.
It occurred to me to take the belt off & see if I cud turn by hand.
To my surprise I was able to - it was hard to turn it in the direction of "up" but I cud see the tower going up as I turned.
I turned it up & down a number of turns thinking that the oil needed swishing around in the gear box.
So, back to raising the tower & to my surprise, it started going up. I had to stop it abt 3/4 of the way up to untangle the coax.
When I restarted it on up, back to the same prob. I got my wife to flip the switch while I prodded the pulley wheel with a piece of wood to start it moving.
After 4-5 "shoves" it started on up & is now sitting at 72 ft ... shud I leave it there til I die??? Sorry, that's a bad joke these days.
After all this I noticed oil had come out of the top of the gear box. I did have the cap on tightly.
One of you suggested a weight issue & provided me with the following info.
"From what I understand, UST rates the 72 foot crank up towers at 200 lbs of antenna(s), rotor and mast, bearing etc weight with 22 lbs of cable weight, 222lbs max vertical dead weight.  The DB36 weighs 165 lbs and the tilt plate about 60 lbs. The mast, rotor, bearing, cables etc would be additional."
So, is it the gear box or is it the weight, or both. :)
Fritz K4OAQ





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